str = "day day up"
for i in range(len(str)):
    print(str[i],end="/")

list1= [1,2,3,4,5]
list1[0] = 1
list1.append(2)
print(list1)


list3 = list();
list3.append(1)
list3.append(2)
list3.append(3)

list2 = [1,2,3]
for i in list2:
    print(i)
list2.insert(1,10) # 在指定位置插入元素
print(list2)

list2.extend([11,12]) # 添加多个元素
print(list2)
print('------------')

# list2.sort() # 默认升序
# print(list2)

list3 = sorted(list2)
print(list2)
print(list3)
# del list3  # 删除变量
# print('++++++++++++')
# print(list3)



list4 = [1,3,5,7,9]
list5 =[i**2 for i in range(1,10) if i%2 !=0]
print(list5)
str = ('111',)
print(str)
